Lisa Lambe says performing with Celtic Woman is allowing her to be herself.

"It is just so nice to be onstage singing as Lisa instead of being a character," says Lambe, whose musical history is in doing roles in plays such as "Sweeney Todd."

Not this year, though. Lambe is the newest member of Celtic Woman, which makes its annual visit to Pittsburgh on Friday at the Consol Energy Center, Uptown.

"It is a fabulous time," she says. "My background is in drama, but I love singing. It suits me very well."

She is the newest member of the group that changes a little in size and personnel almost year to year, but consistently puts on a spectacular show with backup singers and a small orchestra filled with pipes and Irish percussion.

It is a concert, to be sure, but also a show built around sometimes-moody stage settings and dramatic musical presentations conceived by music director and keyboardist David Downes. It is a show that has drawn enthusiastic crowds in Pittsburgh from its first visit in 2005 at the Byham Theater, Downtown, to stops at the Benedum Center and the now-closed Mellon Arena.

The tour started with 16 cities; this year it will visit 65, doing more than one show in several.

Worldwide, Celtic Woman has sold more than 6 million CDs and performed to more than 2 million people.

"The beauty of the show is we have four ladies doing songs that sometimes are the same and sometimes are different," Lambe says. She believes it draws many repeat viewers because "it's the same show but ever-changing."

The show includes great differences in music, from Gaelic favorites, standards such as "Over the Rainbow" and the group's gigantic hits, "You Raise Me Up" and "Orinoco Flow."

The group is largely the same but changing, too, as members come and go to attend to matters ranging from motherhood to other musical possibilities. It has been a quintet, but is a quartet this year including Chloë Agnew, Lisa Kelly and whirling dervish fiddler, Máiréad Nesbitt .

"It is different for everyone," says Lambe, who replaces Lynn Hilary, "but the girls have given me a big welcome, so I am glad to be here."

Lambe, who has a degree in performance from Dublin's Trinity College, has performed as a concert soloist as well as in plays such as "The Improbable Frequency" and "The Shaughraun," for which Downes was musical director.

"So that is how he knew of my singing," she says. "Máiréad Nesbitt was in that show, too."

She credits the musical director with a great deal of the group's success. He is a talented arranger, she says, but also has a strong sense of drama that shapes the musical flow.

She says, for instance, one of her solo pieces, "Dulaman," is a rouser that is meant to kick life into the second half of the show.

All of those elements are making her first U.S. tour with Celtic Woman exciting, she says.